Control system for rocket motors



17, 1953 F. B. HALFORD ET AL CONTROL SYSTEM FOR ROCKET MOTORS Filed Dec. 27, 1949 (COMBFESSEO AVR) Inventor ran/4 BHalford Ari-bur V. Cleaver Erneti- B. Dove se i F 1 MM A ltorneys Patented Nov. 17, 1953 UNITED stares PATENT OFFICE ooNr'noL sYSTEiZ ZZEZmCKE'r Morons I Erank Bernard Halfor tine Qleaver, London East Barnct, Engla Havillan'd Engine Bri d, Edg'ware, Arthur Valenand Ernest Baker Dove, nd, ompany Limited, 3 Stonefgrotve, Eugwar 'E land, a company of Great assignors to The De e-Aiuflic'ation December 27; 1949, Serial Not-135,281

claims priority; application Great Britain January 3, 1949 1 "This invention i-eiat s to cket type propul slon apparatus oi the kind in which proponent liquid or liquids are L-i'mected into a reaction chamber which a reaction takes place accom ipan ied by the evolution oi gases which issue Irom ano'zzle with propulsive enact. H r is an object of the present invention to proville control means tier su'c'h rocket propulsion apparatus which will enable an operator to make certain that the enziparaiais is in operating condition before bringing it into full operation.

According to the present invention a rocket type propulsion anharatus oi the kind specified includes a'starting control which when actuated causes the propellent liquid or liquids to he iniected. into the. reaction chamber, and a thrust selector which set in a. full thrust position when the starting control is actuated allows the propellant liquid or liquids to enter the reaction chamber at the rate for lull thrust, but set in a check thrust only allows the proe .pellent liquid or liquids to enter the reaction chamber at a much reduced rate, hereinafter termed the checking rate. I p I p i The invention is more particularly; although not exclusively, applicable to rocket type propulsion apparatus of the kind whicheco npressed air or gas admitted to the propellent liquid reservoir or reservoirs forces the (propel-lent liquid or liquids-into the reaction chamber. In such an apparatln the rate of fiow of a propellen-t liquid into the reaction chamber depends largely on the pressure of the compressed air or gas which is applied to it, and 'infone form of the invention the'th'rust selector controlska valve, hereinafter termed the check thrust valve, in the compressed ir or gas supply to thereservoir' or reservoirs,

this valve affording ;a.-largel aperture when the thrust selector is in the full thrust position and a considerably smaller a erture when the thrust selector is in the check thrust position. Thus when the selector control is in the latter position there is a considerable pressure drop-at the check thrust valve, so that the pressure applied to the liquids in the reservoirs is "considerably reduced, andwhen the starting control is actuated'the liquids will only enter the reaction chamber'at the checking rate.

The check thrust valvei maybe actuatediebythe compressed air o as which is admitted :to 'one or other of o pair of opposed actuating Of a movable, valve member in dependence-on the position of a pilot valve, which {will-in tum depend onthesetting of the thrust-'seie'ctor.i'- Elie P 0} valvehm'ay conveniently moved agalhst some. (crew-35.6

ergised when a switch cohstitutingthe selector is closed, the spring returning the pilot valve to it's original position when the thrust selector switch is opened.

In cases where the starting cohtrol opens a starting valve in the compressedaair supply electrically by means of a solenoid, the two solenoids may be so connected the star-tin; control switch and the thrust selector switch that when the latter is set in the check thrust position and the starting control switchis actuated both "solenoids will be energised. On the otherhand-when the thrust selector switch is set in the full thrust position and the starting control switch; actuated only-the starting valve solenoid will been? erg-ised. The electricalcircuit may be arranged in various ways to achieve this Safetyvdevices are preferably incorporated for warning the operator, in the event of a failure in the circuit.

There will generally be some iormof nonreturn valve between a propellentliquid-reservo'ir and the reaction chamber. This may (take the form of an injector valve for the admission of Ta propellent liquid, an'dthi's: valve may be so "arranged that when the pressur'e'bf the pr'op'ellent liquid is low, 1. e. when the thrust selector-let inthe checking position, it will only a Iii-ow of propellent liquidlint'o the reaction them;- her at the checking rate, This may be achieved by suitable adjustment of the injector valve spring. Preferably a valve having main now-ans auxiliary flow passages isexnp'ioyeic'i. A vane er "this kind is described the present applicants United States patent specification Serial No. 135,283,fiIedDeceInberWJMQ.

The inve i on may becariiedf mte erect lh :one form or check thrustva'lvej and Figures 3 and 4 are ie euitfaiagrams showing;

alternative arrangement "of the" control circuit. The general r angement ffoiml of rfhe rocketunit is "described 'i inn tedstat s patent ahanrthervaieiiti ie elar jh not eat we tional construction and then through pipe 64 to V v a manually actuated on-ofi or air release valve (described in Patent No. 2,612,019, dated September 30, 1952). When the air release valve is open compressed air flows through it into pipe 25 and thence to the check thrust valve I6, which will be described in detail below. After leaving the check thrust valve [6 the compressed air passes through pipe 26 to a solenoid operated starting valve 11. When this starting valve is opened by actuation of a starting switch compressed air passes through it into pipe 52 and opens a ressure-actuated catalyst air distributor valve 18, which allows compressed air to flow through a pipe l9 and enter the catalyst reservoir 12 and so inject the catalyst into the reaction chamber It. A- portion of the compressed air which has passed through the catalyst air distributor valve 18 flows along a pipe 20 and opens a pressureactuated hydrogen peroxide air distributor valve 21, thus allowing compressed air to flow through a pipe 22 and enter the hydrogen peroxide reservoir II, and so inject hydrogen eroxide into the reaction chamber 10 through an automatic injector valve 23. The hydrogen peroxide thereupon dissociates, producing propellent gases which are expelled through nozzle 63 at high velocity.

'The check thrust valve I 6, as shown in Figure 2, consists of two distinct valve members, namely'a main valve member 24 which, when opened, allows compressed air to pass freely from the air release valve I5 through an inlet passage 25 to 'the starting valve 11 through an outlet passage 25, and a pilot, valve 21 which controls the movements of the mainvalve member 24.

The valve housing 28 is divided by transverse partitions 29, and 30 into three chambers, of

which the upper chamber 31 accommodates a solenoid 32 for. actuating the pilot valve 21. The

centre chamber 33 constitutes a cylinder in which can move a piston 34 connected to the main valve member 24, the space below this piston being always vented to the atmosphere'through a port 35. The third or lower chamber 36 constitutes a compressed air chamber. The space-B5 above the piston 34 is sealed from the center chamber33 by a bellows '48 connected at its upper end to the partition 29 and at its lower end to the piston 34.

A tubular element 31 which accommodates the =pilot'valve 21 extends through the chamber 3| and the space 65 and opens into the third chamher-"36. Themain valve member 24 and the piston 34 canslide freely upon the tubular element'31,but a fluidseal 38 is provided to prevent leakage of air along the sliding surfaces. V Q'There 'is" an annular shoulder 39} in the lower leaves the chamber 36 below the seating. There is a small bypass passage 40 through which air can pass with a substantial pressure drop from the inlet passage 25 to the outlet passage 26 when the main valve member 24 is closed upon its seating 39.

The pilotvalve 21 which, as stated above, is accommodated in the tubular element 31, consists of a double ended'needle valve which can move between two stationary seats 4| and 42 formed in transverse partitions in the tubular element 31 so as to close one or the other. The space between these seats, in Which lies the pilot valve 21, communicates through passages 43 in the wall of the tubular element 31 with the space 55 above the piston 34. The interior of the tubular element below the lower'pilot valve seat 42 communicates with the lower chamber 36, while the part of the tubular element 31 above the upper pilot valve seat 4! communicates with the atmosphere through a port 44 and accommodates the solenoid armature 45, which is attached by a stem 46 to the pilot valve 21. A light spring 41 bears against this armature and urges the pilot valve 21 toe wards its lower seat 42. When the solenoid is energised the armature is forced upwards, compressing this spring and raising .the pilot valve 21 until it bears against its upper seat 4i.

When the pilot valve is in its lower position the space 65 is in communication with the atmosphere, and the pressure, of the compressed air on the underside of the main valve member 24 raises it from its seating'so that the compressed air can flow without hindrance from the inlet passage 25 to the outlet passage 26. I On the other hand, when the solenoid is energised and the pilot valve 21 is raised into its upper position, compressed air enters the space 65 and s0 pushes the piston 34 downwards and forces the main valve member 24 on to its seating. Compressedair can now only pass from the inlet passage 25'to the outlet passage 26 through the restricted passage 40, so that it reachesthe outlet passage 26, and hence eventually the reservoirs H and 12, at a consid erably reduced pressure; Thug whenthe solenoid 32 is energised the propellent liquids willv enter the reaction chamber at the checking rate.

Referring now to Figure 3, the solenoid 49 of the starting valve 11 and the solenoid 32 of the check thrust valve [8 are interconnected with a starting control switch 50 and a thrust selector switch indicated generally at 51; The thrust see lector switch 5| has three positions, an off position 52, a check position 53, and a fire or full operation position 54. Themovable'mem: her of the thrust selector switch is connected "at all times to one terminal of a source of" current 55, while the other terminal of thesource'oi ,c'urf- 'rent is connectedthrough' the 'startingcbntrol chamber 36 which constitutes a seating for the valve member 24;; {The compressed air inlet passage 2,5 entersthechamber, 3 6 above this seat,-

.11 51.1229. 1 2937 422251 29 Pu t;PE SQE i-Lfi switch '50 to one end of both the solenoids 32 and 49. When the thrust selector'switch isgin the check position 53 the movable member cone nects the other ends of thQ'SOlGIlOidS 32 and 49 to the source of current 55, so that as soon as the starting control switch 50 is closed a; current will flow in parallel through both the solenoids 32and 43. When the thrust selector switch 5! isset-in the fire position 54, the circuit through'l' the solenoid 32 of the check thrust valve remains open; so that when the starting control switch 50 is closedionly the starting valve solenoid la wil-l be energised. r

When the thrust selector switch 51 "is in 'the fofi? position, 5.2.,ithe circuits through? both .sole; noids; are open so thatvineither solenoid will be energised even though the starting control switch 50 should inadvertently be closed.

In an alternative circuit shown in Figure 4 the solenoids 32 and 49 are connected in series. In this arrangement the thrust selector switch 56 is arranged so that when in the "011 position 51 no current will flow through either solenoid. When in the check position 58 a current will flow in series through both the solenoid 32 and 49, and while in the fire position 59 a current will flow only through the solenoid 49 when the starting control switch 50 is closed.

Indicating lamps 60 and 6! or other safety devices are provided in the circuits of Figure 3 and Figure 4 so that the operator can be sure that the starting solenoid 49 will be energised and the check thrust solenoid 92 will be deenergised whenever full thrust is required.

It will be appreciated that many modifications may be made to the arrangements described. For instance electrical operation of the check thrust valve is not essential, since mechanical, hydraulic or pneumatic means can be provided for actuating the pilot valve 2! in the arrangement described above.

What we claim as our invention and desire to secure by Letters Patent is:

1. Rocket propulsion apparatus comprising at least one reservoir for propellent liquid, a storage container for a gaseous pressure medium, a reaction chamber, a propulsion nozzle extending rearwardly from said reaction chamber, a pressure medium conduit from said storage container to said reservoir, a propellent conduit from said reservoir to said reaction chamber, a starting control valve in said pressure medium conduit for initiating the propellent injection, a thrust selector, a check thrust valve in said pressure medium conduit upstream of said starting control valve, said check thrust valve having a main valve member and a large aperture and a throttling aperture which apertures are selectively controlled by said main valve member, and actuating means for said main valve member responsive to the setting of the thrust selector adapted when the thrust selector is set in one position to hold said main valve member in one end position with the large aperture open and, when the thrust selector is set in another position, to hold said main valve member in its other end position in which said large aperture is closed and only the throttling aperture is open.

2. Rocket propulsion apparatus as claimed in claim 1, in which the check thrust valve includes a pressure sensitive actuating device for said main valve member adapted when subjected to super-atmospheric pressure to hold said main valve member in its end position in which said large aperture is closed, passage means communicating with said actuating device, a pilot valve in said passage means adapted in one position to open said passage means only to the gaseous pressure medium and in another position to open said passage means only to the atmosphere, and an operative connection between said thrust selector and said pilot valve for determining the position of said pilot valve in accordance with the setting of the thrust selector.

3. Rocket propulsion apparatus as claimed in claim 1, in which the check thrust valve includes a pilot valve, a spring urging said pilot valve towards one end position, and a solenoid which is adapted when energised to move said pilot valve towards an opposite end position in opposition to said spring, the thrust selector comprises a circuit-controlling switch adapted when in one setting to energise said solenoid and when in another setting to de-energise said solenoid, and the movable valve member includes a pair of opposed actuating surfaces adapted to be selectively exposed to the gaseous pressure medium in dependence on the position of the pilot valve whereby when the pilot valve is in one position one of said opposed surfaces is exposed to the gaseous pressure medium and the main valve member is urged into one end position whereas when the pilot valve is in another position the other of said opposed surfaces is exposed to the gaseous pressure medium and the main valve member is urged into its other end position.

4. Rocket propulsion apparatus comprising at least one reservoir for propellent liquid, a reaction chamber, a propulsion nozzle extending rearwardly from said reaction chamber, means for injecting propellent liquid from said reservoir into said reaction chamber for gas-producing reaction therein, a solenoid-operated starting valve for initiating the propellent injection, a solenoidoperated check thrust valve, a starting switch, a thrust selector switch, an electric current supply, and an electric circuit connecting said solenoids, said switches, and the said supply, and adapted so that when the thrust selector switch is in one position and the starting switch is closed both solenoids are connected to the electric current supply, but when the thrust selector witch is in another position and the starting switch is closed only the starting valve solenoid is connected to the electric current supply.

5. Rocket propulsion apparatus as claimed in claim 4, in which the thrust selector switch is arranged so that when set in a third position both solenoids are disconnected from the electric current supply.

FRANK BERNARD HALFORD. ARTHUR VALENTINE CLEAVER.

ERNEST BAKER DOVE. References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 670,563 Morris Mar. 26, 1901 1,194,965 Darrow Aug. 15, 1916 1,925,301 Campbell Sept. 5, 1933 2,139,064 Beattie Dec. 6, 1938 2,192,042 Hofimann Feb. 27, 1940 2,397,659 Goddard Apr. 2, 1946 2,470,564 Lawrence May 17, 1949 2,479,888 Wyld Aug. 23, 1949 2,496,553 Littlefield Feb. 7, 1950 OTHER REFERENCES Journal of the American Rocket Society; No. 72; December 1947; pages 28, 29, 47 and 48. 

